喉咽后壁区癌手术治疗

目的探讨喉咽后壁区癌的手术方法、疗效和保留喉功能的可行性。方法回顾性分析于1997～2003年行手术治疗的喉咽后壁区癌21例。男19例,女2例;年龄35～78岁;根据1971年UICC分期的规定:Ⅰ期2例,Ⅱ期3例,Ⅲ期4例,Ⅳ期12例。6例以局部黏膜拉拢缝合修复,2例行裂层皮瓣修复,1例行颈阔肌皮瓣修复,7例以残喉气管瓣修复,1例行胸大肌皮瓣修复,1例以胸大肌联合喉气管瓣修复,其余3例行全喉及全喉咽切除后以胃上提及结肠上徙修复。10例行单侧,11例行双侧选择性或改良根治性颈清扫术。术后病理5例有淋巴结转移,占23.8%。19例术后行辅助性放疗。结果21例术后均Ⅰ期愈合,吞咽功能恢复良好,其中11例保留了全部或部分喉功能。经6个月～7年随访,随访5年及以上者3例,健在1例,生存率1/3;随访3年以上者13例,健在5例,生存率38.5%;其余8例随访未及3年。结论喉咽后壁区癌的T1￣2级病变宜行保留全喉功能的手术,细心选择的T3￣4级病变可保留部分喉功能,手术方式和重建方法的选择对彻底切除喉咽后壁区癌并保留喉功能十分重要。     

Transformation of the shape of the ethmoid bone during the course of life

The ethmoid bone undergoes significant changes in the course of life. The critical period is the time from 9 to 35 years of age. The changes in its shape depend upon the intensity of pneumatization of the ethmoid labyrinth and frontal sinus. If pneumatization of the labyrinth is excessive, the ethmoidal cells are not covered by the frontal bone. On the contrary, they are incorporated in the inferior floor of the anterior cranial fossa, resulting in a possible risk of penetration during surgical ethmoidectomy.     

On the High Frequency Transfer of Mechanical Stimuli from the Surface of the Head to the Macular Neuroepithelium of the Mouse

Vestibular macular sensors are activated by a shearing motion between the otoconial membrane and underlying receptor epithelium. Shearing motion and sensory activation in response to an externally induced head motion do not occur instantaneously. The mechanically reactive elastic and inertial properties of the intervening tissue introduce temporal constraints on the transfer of the stimulus to sensors. Treating the otoconial sensory apparatus as an overdamped second-order mechanical system, we measured the governing long time constant (Τ_L) for stimulus transfer from the head surface to epithelium. This provided the basis to estimate the corresponding upper cutoff for the frequency response curve for mouse otoconial organs. A velocity step excitation was used as the forcing function. Hypothetically, the onset of the mechanical response to a step excitation follows an exponential rise having the form Vel_shear = U(1-e^−t/TL), where U is the applied shearing velocity step amplitude. The response time of the otoconial apparatus was estimated based on the activation threshold of macular neural responses to step stimuli having durations between 0.1 and 2.0 ms. Twenty adult C57BL/6 J mice were evaluated. Animals were anesthetized. The head was secured to a shaker platform using a non-invasive head clip or implanted skull screws. The shaker was driven to produce a theoretical forcing step velocity excitation at the otoconial organ. Vestibular sensory evoked potentials (VsEPs) were recorded to measure the threshold for macular neural activation. The duration of the applied step motion was reduced systematically from 2 to 0.1 ms and response threshold determined for each duration (nine durations). Hypothetically, the threshold of activation will increase according to the decrease in velocity transfer occurring at shorter step durations. The relationship between neural threshold and stimulus step duration was characterized. Activation threshold increased exponentially as velocity step duration decreased below 1.0 ms. The time constants associated with the exponential curve were Τ_L = 0.50 ms for the head clip coupling and T_L = 0.79 ms for skull screw preparation. These corresponded to upper −3 dB frequency cutoff points of approximately 318 and 201 Hz, respectively. T_L ranged from 224 to 379 across individual animals using the head clip coupling. The findings were consistent with a second-order mass-spring mechanical system. Threshold data were also fitted to underdamped models post hoc. The underdamped fits suggested natural resonance frequencies on the order of 278 to 448 Hz as well as the idea that macular systems in mammals are less damped than generally acknowledged. Although estimated indirectly, it is argued that these time constants reflect largely if not entirely the mechanics of transfer to the sensory apparatus. The estimated governing time constant of 0.50 ms for composite data predicts high frequency cutoffs of at least 318 Hz for the intact otoconial apparatus of the mouse.     

镫骨赝附体与砧骨长脚之间连接状态对声音传导的影响

目的探讨镫骨赝附体与砧骨长脚间连接程度对声音传导的影响,为镫骨手术寻找理论依据和更好的指导临床工作.方法17例新鲜尸体颞骨标本,在不同强度的机械刺激下,采用激光多普勒振动仪研究镫骨赝附体与砧骨长脚间不同的连接程度对声音传导的影响.结果将镫骨赝附体与砧骨长脚的连接程度,由三位医师分别对内镜和扫描电镜在颞骨标本中采集的镫骨赝附体与砧骨长脚之间连接的图像进行评分,分为紧密连接、松弛连接和未连接,三位医师的评分结果基本一致.分别对上述三种连接程度,在500mV、800mV和1200 mV的机械刺激下,用激光多普勒振动仪测试砧骨长脚侧与镫骨赝附体间的振动差距,经过专门的计算机软件处理,换算为声刺激模式,发现紧密连接时,声音的传导在此连接上损失2 dB,小于砧镫关节生理性的声损失3 dB,松弛连接和未连接对声音的传导在此连接上的损失很大,高达28 dB不等,平均为10 dB.结论镫骨手术时镫骨赝附体与砧骨长脚连接紧密,声传导损失接近砧镫关节的生理性声传导损失.